Individuals with neurofibromatosis type 2 (NF2/Merlin), commonly suffer severe dry eye issues.
Tumor growth on different nerves in the skull, schwannoma tumors, can result in nerve damage and cause either dry or watery eyes. Also, tumor drug treatments commonly result in body-wide dehydration to the eyes and major organs.
When the eye blinks a tear is meant to wash a tear over the eye surface and also maintain an oil barrier, both are needed to protect the cornea from scratches and bacteria that would otherwise cause risk of infection. If not properly lubricated the eye is at risk of cracked cornea issues; depending how damaged the cornea is, number of cracks, and depth of the cracks, the individual is at risk of a permanently damage vision, and can lead to corneal blindness.
If an individual is experiencing early symptoms or complete loss of function of either the 1) facial nerve (cranial nerve 7), or 2) the trigeminal nerve (cranial nerve 5) resulting in trigeminal neuralgia, the eye may either produce fluids to protect the eye properly. However; 3) medications including either chemotherapy, or molecular target tumor treatments, commonly result in a side effect of whole body dehydration including dehydration of fluids necessary for the eyes.
Dry eyes can be the result of the start of Cranial Nerve 7 (CN7) Facial Nerve damage and eye drops might be needed regularly, the preservatives found in bottled eye drops are often irritating when used in excess and single use eye drop options are helpful.
However, if the Facial Nerve is completely broken, eye drops will not stay in the eye long and quickly drip out of the eye, making it necessary to use a heavier ointment or gel. The heavier the gel is the longer it will keep the eye moist, but can cause blurriness. It is important for each individual to try different options to determine what works best for them.
Dry eyes can also be the result of CN5 the Trigeminal Nerve. CN7 is primarily responsible for face movement, but CN5 is primarily responsible for the ability to feel the face but also includes a part of the face that helps with eye moisture. This can be even more dangerous than Facial Nerve dry eyes because an individual with dry eyes would not feel the irritation to know when or if drops or gel is needed.
Many of the tumor suppressors can result in dry eyes including; Bevacizumab (Avastin™), Lapatinib (Tykerb™) and RAD 001 - Everolimus (Afinitor™). These medications can cause dry eye issues and require excessive individuals to drink more water to compensate.
Dry Eye issues a result of Avastin, typically only results for the first 3 months of treatment. When taking medications that cause dry eye issues, the eye issues stop when medication is discontinued.
Simple solutions to manage dry eyes:
Preservative free eye drops, ointment or gel might be necessary if an eye does not tear when it blinks. These options can help keep your eye moist for a much longer period of time then regular eye drops. Some top choices by people in the NF2 community include:
If dry eye issues do not resolve on their own, some of the following should be considered:
These lenses are available in different brands and which is ideal should be considered after reviewing all brand advantages and disadvantages.
This lens may help if suffering from:
Scleral Lenses are available worldwide, different brands and manufacturers. One option in the United States and Canada is BostonSight under the name PROSE (prosthetic replacement of the ocular surface ecosystem)
There are different forms of eyelid implant weights; some are thinner than others, while some contour to the eye better.
The gold weight is the most commonly used and might eventually need to be replaced with a platinum weight if irritation develops.
This offers options of limiting eye exposure. It can help retain moisture and can also help protect the eye. This surgical option is not always a very cosmetic friendly option, but can be helpful in saving vision.
Some eye tightening techniques to look into include; Eyelid Spring, Lateral Canthal Sling, Palpebral Eyelid Spring, Lateral or Central Tarsorrhaphy, and medial lee canthoplasty.